[K/N] Add test for inlining of adopted function reference

^KT-48179

kotlin-native/backend.native/tests/filecheck/adopted_function_reference.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+inline fun foo(x: () -> Unit): String {
+    x()
+    return "OK"
+}
+
+fun String.id(s: String = this, vararg xs: Int): String = s
+
+// CHECK-LABEL: "kfun:#main(){}"
+fun main() {
+    // CHECK-LABEL: entry
+    // CHECK-NOT: call %struct.ObjHeader* @AllocInstance
+    // CHECK-NOT: alloca
+    val x = foo("Fail"::id)
+    println(x)
+    // CHECK-LABEL: epilogue
+}